Disc drives are data storage devices that store digital data in magnetic form on a rotating storage medium on a disc. Modem disc drives comprise one or more rigid discs that are coated with a magnetizable medium and mounted on the hub of a spindle motor for rotation at a constant high speed. Information is stored on the discs in a plurality of concentric circular tracks typically by an array of transducers ("heads") mounted to a radial actuator for movement of the heads relative to the discs. Each of the concentric tracks is generally divided into a plurality of separately addressable data sectors. The read/write transducer, e.g. a magnetoresistive read/write head, is used to transfer data between a desired track and an external environment. During a write operation, data is written onto the disc track and during a read operation the head senses the data previously written on the disc track and transfers the information to the external environment. Critical to both of these operations is the accurate locating of the head over the center of the desired track.
The heads are mounted via flexures at the ends of a plurality of actuator arms that project radially outward from the actuator body. The actuator body pivots about a shaft mounted to the disc drive housing at a position closely adjacent the outer extreme of the discs. The pivot shaft is parallel with the axis of rotation of the spindle motor and the discs, so that the heads move in a plane parallel with the surfaces of the discs.
Typically, such radial actuators employ a voice coil motor to position the heads with respect to the disc surfaces. The actuator voice coil motor includes a coil mounted on the side of the actuator body opposite the head arms so as to be immersed in the magnetic field of a magnetic circuit comprising one or more permanent magnets and magnetically permeable pole pieces. When controlled direct current (DC) is passed through the coil, an electromagnetic field is set up which interacts with the magnetic field of the magnetic circuit to cause the coil to move in accordance with the well-known Lorentz relationship. As the coil moves, the actuator body pivots about the pivot shaft and the heads move across the disc surfaces. The actuator thus allows the head to move back and forth in an arcuate fashion between an inner radius and an outer radius of the discs.
A majority of the disc drive's essential electronics are mounted on the printed circuit board assembly ("PCBA"). The PCBA is fastened to the bottom exterior surface of the drive and includes electrical components that manage the operations of the disc drive. For example, the PCBA includes electrical components that control the speed of the spindle and position of the actuator arms over the discs. Similarly, the PCBA also includes electrical components that interface with the computer's processor.
Seagate Technology, the assignee of the present invention, currently has installed a metal cover over the PCBA to protect the board, and hence the disc drive's essential electronic circuitry, from electrostatic discharge. The cover also makes disc drive installation less time consuming and less likely to result in damage to the PCBA.
However, in using this metal cover to protect the PCBA, the electrical components mounted on the PCBA are essentially enclosed between the disc drive base deck and the protective cover. As such, the PCBA is not in direct airflow and the ability of the electrical components to effectively dissipate heat generated during operation of the disc drive may be reduced. As efforts continue toward chip consolidation, the risk of overheating increases. Electrical component overheating may cause the PCBA to malfunction due to excessive heating. Accordingly, there is a need for a means for improving heat dissipation in disc drives which include a PCBA protective cover.
The present invention provides solutions to the above and other problems and offers advantages over the prior solutions to the above and other problems. These and various other features as well as advantages which characterize the present invention will be apparent upon reading of the following detailed description and review of the associated drawings.